Cranes



States CRANES Arnold Hallsworth, Sunderland, England, assignor to Steels Engineering Products Limited, Sunderland, Eng- The present invention relates to cranes and more particularly to a jib crane for handling bulky loadswithout permitting undue swinging of the load.

According to the present invention a jib crane includes as a part of the jib a guideway extending upwardly along the jib and a carriage adapted to carry the load and the directional movement of which is controlled by the guideway.

In a preferred form the main element of the jib carries or has incorporated in it the guideway which is substanatially vertical when in operation and the carriage projects substantially horizontally from the guideway along which it is movable by means of a hoist rope operated by the normal hoist motion of the crane.

The invention has particular application to a mobile crane having a slewing superstructure and for use inter alia for loading bulky loads such as railway containers onto trucks or lorries. When such containers are loaded onto or off railway trucks it is usually in places where swinging of the load during movement of the jib is undesirable.

The invention will now be described with reference to the accompanying drawing in which:

FIGURE 1 shows diagrammatically in side elevation a mobile crane carrying a jib crane constructed in accordance with the present invention, and

FIGURE 2 shows an alternative construction of a detail of the crane.

In the embodiment shown the jib crane is mounted upon a mobile chassis 1 and is provided with a slewing superstructure 2 of known construction. The crane jib 3 which is pivoted about a horizontal axis 4 at its lower end to the superstructure 2 consists essentially of a T shaped structure the vertical leg 5 of which is of I section to form a restraining guideway for a carriage 6 extending substantially horizontally from the jib 3 so that the directional movement of the carriage 6 is restrained to a path parallel with the vertical leg 5 of the jib 3. Conveniently the carriage 6 engages the guideway in the leg 5 by means of rollers 7 which the carriage carries on either side of the leg 5 to engage the flanges of the I section.

The up and down movement of the carriage 6 is controlled by a hoist rope 8 operated in normal manner from the cab 9 of the crane and passes over pulleys on the cross piece 10 of the T shaped jib 3.

The elevation of the jib 3 is controlled by a derrick reeving 11 extending from the superstructure 2 to the rear end of the crosspiece 10 of the jib 3.

Th carriage 6 is provided with means for engaging the load shown diagrammatically as a railway container 12 and may for example comprise spaced eyes 13 which engage tackle 14 passing round the load or extending from opposite edges of the load. By engaging the load in this manner undue swinging of the load on the carriage 6 is prevented. This may be enhanced by securing the load 12 relatively closely to the carriage 6.

In use the carriage 6 is positioned above the load shown in chain line upon the ground by the multiple hoist reeving 8 and lowered to a position where the load can be attached to the carriage 6 by the tackle 14 or by such other means as are provided. After the load has been secured to the carriage 6 the carriage 6 is raised to the required height for travelling and for example may be raised to the position shown in chain dotted line 15. To secure the load for travelling once it is raised to the height shown or to any other desired height the jib 3 is derricked back by the derrick reeving 11 to a position shown in chain line 16 and against limiting stops which may be of the shock absorber kind such'for example as a ram type buffer 17. In the position shown in chain line 16 the vertical leg 5 of the jib 3 lies inclined backwardly towards the superstructure and this causes the load 12 to lie against the vertical leg 5 of the jib 3 so to substantially eliminate any possibility of the load swinging from side to side as the mobile crane is manoeuvred about. Consequently the load can be moved about from one point to another in the minimum space required for manoeuvring the crane substantially no room having to be provided or allowed for the swinging of the load.

In certain circumstances the stiffnes of this multifilar suspension has been found to be too high, and to simplify placing the load onto a standing truck, it has been found advisable to carry the spaced eyes (13) on a rotatable sub-frame 20 as shown in FIGURE 2. In this construction the frame 20 carries the spaced eyes 13 and is rotatably suspended from the carriage 6 for example on a centre post 22 in conjunction with rollers or thrust bearing 23. In this way the load can be rotated when hanging free of the jib to be aligned with the truck or wagon for correct placing thereon.

To deposit the load the crane is manoeuvred so that the load is brought above the point of deposit and the jib allowed to move forwardly under the weight of the load to a substantially vertical position, whereupon the carriage is lowered along its guideway till the load is upon the ground or other receiving urface.

A crane constructed in accordance with the present invention and mounted upon a slewing superstructure permits the load to be picked up over the side or end of a wagon or truck and then hoisted and slewed to clear obstruction. Whilst the invention has been described with particular reference to a slewing crane the invention may also be applied to other forms of cranes where a minimum swing of the load is required during movement of the jib.

The invention is of particular application to cranes of the mobile type where heavy loads are involved because all loading on the jib mast apart from direct thrust is reduced to negligible proportions.

I claim:

1. A jib crane including a slewing superstructure, a jib mast, means pivotally connecting the lower end of said jib mast to said superstructure for pivotal movement in a vertical plane forwardly of its pivotal support on the superstructure, said superstructure taking the entire weight of the mast, said mast having a T formation and a guideway which extends along the stem of the T, a load carrying carriage having means supporting it in said guideway for movement therealong, one limb of the head of the T mast having anchoring means for rope tackle for controlling the elevation of the mast and holding it in a vertical position against said pivotal move ment forwardly of its pivotal support on the superstructure, and the other limb having anchoring means for rope tackle for controlling movement of the carriage along said guideway, rope tackle carried by said first mentioned anchoring means and operatively associated with the hoist motion of the crane and hoisting rope tackle carried by said second mentioned anchoring means and operatively connected to the carriage.

2. A jib crane as claimed in claim 1 in which the jib mast is pivotally connected at its lower end to the superstructure for pivotal movement in the vertical plane Patented Oct. 30, 1962 both forwardly and rearwardly of its pivotal support on the superstructure and in which the rope tackle carried by the first mentioned anchoring means constitutes derrick reeving, the arrangement being such that the jib mast can be denricked rearwardly of its pivotal support on the superstructure for the load on the carriage to swing and bear against the jib mast.

3. A jib crane including a slewing superstructure, a jib mast, means pivotally connecting the lower end of said jib mast to said superstructure for pivotal movement in a vertical plane both forwardly and rearwardly of its pivotal support on the superstructure, said superstructure taking the entire weight of the mast, said mast having a T formation and a guideway which extends along the stern of the T, a load carrying carriage having means supporting it in said guideway for movement therealong, one limb of the head of the T mast having anchoring means for rope tackle for controlling the elevation of the mast and holding it in a vertical position against said pivotal movement forwardly of its pivotal support on the superstructure and the other limb having anchoring means for rope tackle for controlling movement of the carriage along said guideway, rope-tackle-derrick-reeving carried by said first mentioned anchoring means and operatively associated with the hoist motion of the crane, the arrangement being such that the jib mast can be derricked rearwardy about its pivotal support on the superstructure for the load on the carriage to swing and bear against the jib mast, hoisting rope tackle carried by said second mentioned anchoring means and operatively connected to the carriage and shock absorbing stops against which the jib mast rests in its rearwardly inclined position.

References Cited in the file of this patent UNITED STATES PATENTS 2,646,182 Maas July 21, 1953 2,832,489 Bailey Apr. 29, 1958 2,897,991 Wagner Aug. 4, 1959 2,941,685 McCune July 21, 1960 FOREIGN PATENTS 614,445 Great Britain Dec. 15, 1948 OTHER REFERENCES German specification 1,013,405, printed Aug. 8, 1957. 

